During the last few years, the Nelson Mail has followed former Richmond man Hap Cameron on his personal challenge to live and work in every continent before he turned 30. Now he's done it, and he's written a book about his quest. He tells Naomi Arnold about nine years experiencing the vagaries of life, love, and the preciousness of both.

On a cold night in mid-April, Nelson climbing gym Vertical Limits hosted the world premiere of Mark ‘Hap' Cameron and Richard Sidey's documentary, Bikes for Africa, an attempt to help set up a sustainable bike workshop in rural Namibia.

The audience flopped onto the bouldering mats and sank into beanbags, and Cameron gave a light-hearted warning that the film, made during the previous two years with his girlfriend at the time, American Mandy Todd, contained some pretty deep emotional stuff about their break-up. In front of his friends, family and well-wishers, the 30-year-old was keeping up his jovial front: Happy-go-lucky Hap, dropping back into little old Nelson after his amazing travels, with a book deal that would become Hap Working the World, released nationwide next week.

But most of the audience didn't know that during those months at home, he was grappling with depression, going through some pretty deep emotional stuff himself.

You might remember Hap Cameron from the pages of this newspaper. He grew up in Richmond, was head boy at Waimea College, and studied marketing and management at the University of Otago. Like so many of his peers, he finished university with a $30,000 student loan and a chronic case of itchy feet. As a 21-year-old on an Outward Bound course in summer 2003, he set his goal: He would live and work on every continent in the world before he turned 30 on 11/11/11. Thirty seemed like a long time away then, with the glorious years of his 20s stretching away in front of him until he'd supposedly start amassing the collective weights of marriage, mortgage, career, and kids.

A young buck off on his own, Cameron hopped around the world, teaching English in South Korea; tutoring a wealthy student in Spain; working illegally putting up tents for the US Open; drilling for oil and working as a toilet attendant and chocolate maker in Canada; and volunteering at an orphanage in Mexico, where he met Mandy. After a blissful holiday in Colombia they decided to return to the United States together.

But as he tried to enter the US his tent work was picked up and he was denied entry, spending a night in jail. Banned from the US for 10 years, it was home to New Zealand, where he caught up with friends now embarking on careers, the loose days of their early 20s behind them - including his best mate Barney, with whom he'd shared some memorable years of travel. Now 26, Cameron started to feel twinges of doubt about his lifestyle and his dream.

"What was I doing with my life?" he writes in his book. "I had no direction. I would stay at Barney's flat some nights, sleeping on the lounge room floor. In the morning all his flatmates were off to work in the city's law and accounting firms wearing their smartly ironed shirts. They would innocently ask me what I was doing - a question that ripped the enthusiasm out of my larger-than-life, live-the-dream demeanour."

A few weeks later, on a family holiday in the Marlborough Sounds, he and his sister Jarnia slipped from a rope swing and fell more than six metres into the trees, with Cameron landing heavily on his neck. Both tumbled another 10 metres down the steep bush slope. A bright flash went off before his eyes; he'd cracked a vertebra in the middle of his back. A temporary blindness poured over him, bringing with it a cold terror. Ellie, a friend since childhood, stroked his head, comforting him.

But lying there, waiting for the rescue helicopter to come, with his big sister groaning from broken ribs next to him, he gained a rare moment of clarity: His challenge wasn't stupid. He wasn't wasting his time.

"I had just been taught a great lesson: Life can be taken away from you on a sunny, comfortable Sunday afternoon while you're with your family, so you have to live your dream," he writes in his book. "You don't want to be lying on a forest floor contemplating a future of being blind and in a wheelchair wishing you had lived your dream."

The goal would totally consume his life for the next four years.

Newly energised, Cameron spent three months recuperating, and started writing a blog documenting his travel adventures. After he recovered, he worked what turned out to be his favourite job as an expedition field assistant in the Australian Outback, and then moved with Mandy to Paraguay, where he became a storyteller. But it was there, as he struggled mightily to find work in his second-to-last continent, Antarctica, that he started to feel the first trickle of depression creeping into his mind, and he had what he calls his "meltdown". After hundreds of rejections, he managed to fib his way onto a six-star luxury Antarctic cruise ship to work hellish hours as a waiter, before he and Mandy moved to Melbourne to prepare for their last stop, Africa. With Cameron banned from the States and not sure what his life would look like after his goal was over, the couple pushed aside the spectre of what might happen next.

Wanting to give back after nearly a decade of crashing on mates' couches, the pair teamed up with Bicycles for Humanity and the Bicycling Empowerment Network Namibia to build an economically sustainable bike workshop in rural Namibia, bringing a container-load of second-hand bikes donated from the people of Melbourne.

But it was there, in his final continent, that Cameron forced himself to break up with Mandy - so, as he explains later in the book, he could sort out his own life "and stop destroying her life with my uncertainty".

He'd always kept the quote "Regrets over yesterday and worries about tomorrow are the twin thieves that rob you of the moment," close to his heart, getting two enormous thieves tattooed on his lower back in Canada. Now the "worries about tomorrow thief" was there with them, hanging over both as they tried to figure out how to make their relationship work: A life, visas, employment, and a home for both of them. After they broke up - much of which they captured on video for their film - Mandy left him behind to finish his goal.

The Hap Cameron that completed his decade-long quest was very different from the one that had started. Months later, after cycling 2000 kilometres through southern Africa, he felt no elation as he stood on the top of Mt Kilimanjaro, on the roof of Africa,

watching dawn breaking on his 30th birthday. Nothing but exhaustion and sadness.

"Before the trek I had visions of giving an inspirational speech at the top," he writes. "Instead, all that came out of my mouth was a vacant emotionless ‘I'm knackered'. Looking back, it perfectly summed up everything: I was knackered. This goal had been my life. I had achieved it with no regrets, but it had taken its toll on me . . . I was ready for my goal to be over. I think I had been ready for a while."

After Africa gave him a final kick in the guts when he was robbed in Dar es Salaam, Tanzania's largest city, he arrived home in Nelson in spring 2011, with 23 kilograms of personal possessions packed into his weathered, flag-covered pack and not a cent to his name. The Nelson Mail reported jauntily that he was getting into writing his book. Looking forward to editing his film. Hoping to inspire young Kiwis. A young man returning triumphant from a great adventure with a book deal that the recipients of his bulk emails had long predicted, and appearances on television and radio. Enough, perhaps, to finally shut up the "real job" questions for a while. What 30-year-old wouldn't want that?

But after the buzz of arriving home, the holidays, and New Year 2012 spent with a close group of friends, he sank back into depression and anxiety, spending hours crying in his counsellor's office, unable to make the tiniest decisions - even about what to put on his breakfast toast. He'd worked more than 25 jobs over the last nine years. As he entered his much-anticipated fourth decade, he was under a substantial black cloud. He couldn't shake the feeling that there was only one match for him - and he'd waved goodbye to her in Zambia.

He spent long days agonising over his laptop, struggling to write about the happy times with Mandy, his partner in his strange, nomadic life for nearly five years; and wondering if he'd made the biggest mistake of his life in breaking up with her. Everyone, including the Mail, kept asking: ‘Hap, what are you going to do now?'

"When the hell were people going to stop asking that question?" he writes in the book. "I knew the answer. They would stop asking me that question when I stopped asking it of myself."

Finally, after beginning anti-depressants and making his first phone call to Mandy as "friends" - where she told him she was seeing another Kiwi - he began to figure it out. By June 2012, two months after that documentary screening at the climbing gym in Nelson, Cameron was pulling out of his deep pit, cutting the pills down to one every second day, and working back in Western Australia.

Now he says he learned more during that last shattering year than the previous eight put together. He figured out how to be an author, for one. He'll be in Nelson in the middle of November promoting the release of Hap Working the World, which he says was incredibly difficult to write. "I'd done a lot of writing, but I love being around people and sharing my stories," he says. "I found the writing process was quite hard - it's a solitary vocation, just you sitting down each day with your computer and having to write."

The film has won the Special Jury Award at the 2012 New Zealand Mountain Film Festival, and he and Richard Sidey have made it available as a free download so others around the world can use it for charity fundraisers in their communities.

He's developing a career as an inspirational speaker, and on Wednesday night appeared at his first travel evening, jointly organised by STA Travel and his publishers. He reports an evening filled with heaps of laughs, enthusiasm and excitement. They're marketing Cameron as an "OE Expert", and with good reason. Hap Working the World is crammed with people and stories, plenty of beers, tears, and good times. He develops from a 21-year-old kicking up his heels to a 30-year-old who's not so sure he has all the answers any more - but knows he doesn't want to be boozing and partying and chasing girls. Not as much, anyway.

"I just want to help other people," he says. "[A lot] in my book is focused on the younger age group; they see this adventurous funny guy. Well, there were some pretty bloody tough times.

"When they read it, I want people to remember back to their early 20s. People forget about what they were like in their early 20s - but that 30-year-old standing on top of Kilimanjaro is very different. The goal stays constant the whole way but the guy trying to achieve it changes and the reader sees it quite vividly."

What sort of advice will he be imparting to those youths about to take off overseas, toting their own new backpack? Don't get your travel advice from the six o'clock news, he says. Commit to what you want to do and take the next step towards making it a reality. And don't go into student debt because everyone else is - unless you're absolutely passionate about what you're studying.

Above all, he says, your worst moments are probably going to turn out to be your best.

"When I had my big accident and got kicked out of the States, that was amazing because I probably wouldn't have had this book otherwise. Looking back it was probably the best thing that could have happened to me.

"It puts everything into perspective; [I realised] actually, I'm doing what I want to be doing."

Cameron considers the book's most painfully intimate moments as one of its biggest strengths.

"I just wanted to be brutally honest," he says. "There's no use hiding behind a facade; the best books I read are the ones that are honest."

He's a big fan of Andre Agassi's revelatory autobiography, and even Eat Pray Love: "I know, I'm such a girl."

"This is just another chapter of your book," his childhood friend Ellie said as she cradled his head while he lay blind and petrified on that steep hillside in the Marlborough Sounds. Ellie was right, it was. Chapter 11, to be exact.

Yet the tale isn't quite finished. In July this year, Cameron proposed to Mandy on a jetty at Anakiwa in Nydia Bay, almost exactly a year after they'd split up. She said yes on the same spot he'd set his working-the-world goal 10 years before, and they were married in August. It makes for a satisfying ending to his story, and the perfect start of a new one. Hap Cameron has always had a knack for a good yarn.

Hap Cameron will be home in Nelson for speaking appearances in mid-November. Keep an eye on the Nelson Mail's Thursday Entertainment page for dates, or visit hapcameron.com to stay updated.